DESCRIPTION: (Applicant's Abstract) The aim of the proposed small grant project is to examine the hierarchical nature of substance use, accounting for the interdependence of family data, using existing databases and sophisticated analytic techniques. Family level and individual level research questions will be addressed. Models will specify the interdependence of parents and adolescents (siblings and target adolescents) on patterns of drug use and deviant behaviors. The impact of family level variables and other contextual characteristics, on family substance use and deviant behavior will also be studied. Typical analyses of family data ignore the potential interdependence and hierarchical nature of the data. In this proposal, new analytical techniques suited to a hierarchical data structure will be employed. These techniques, labeled hierarchical or multilevel models, take into account correlated observations and observations from heterogeneous populations with varying parameter values that often arise in hierarchical data collections. A great deal of time and money has been expended to obtain excellent data sets relevant to an examination of non random clustering of substance use, but many of these data sets have not been analyzed using stage-of-the-art analytic techniques specifically designed for hierarchical data. The hierarchical nature of the data to be examined will allow us to construct, estimate, and test a variety of complex models concerning substance use at both the family and individual level. Tests of major theoretical relationships using different analytic techniques, and comparisons of findings across datasets is likely to yield important information regarding adolescent substance use and other related problem behaviors that might otherwise go unexplored in these datasets. Examination at multiple levels of the hierarchy is likely to further enhance our understanding of the role of families, and the larger social context, in the development of substance use and related deviant behaviors.